I am using Firefox 5 and everything seems to be going fine, but then all of a sudden it stops connecting to the internet. When I try to load a new page, it either says "connecting" and never connects or it says "Problem loading page." This is not a problem with the internet, since every other browser (including Firefox 3.6) can still load pages.

Usually Firefox works for a while, and after I've been using it for about 30 minutes it abruptly stops working. It starts working again if I restart the browser.